Stair tread



FIG. 1 is a perspective view for a design for a stair tread according to the invention;

FIG. 2 is a front elevational view for the design for a stair tread; and,

FIG. 3 is a top plan view for the design for a stair tread.

The figures illustrate a stair tread in which the forward portion of the stair tread and the remainder of the stair tread have a visually contrasting appearance as shown by the line shading on the forward portion of the stair tread and the stippling on the remainder of the stair tread. 

CLAIM The ornamental design for a stair tread, as shown and described. 